The background of the invention will be set forth in two parts.
1. Field of the Invention
This invention relates to microwave devices and more particularly to transmission line switches.
2. Description of the Prior Art
As the communication satellite art has developed, it has become apparent that the ability to switch on a particular directional satellite-mounted antenna aimed at a desired location on earth while the spacecraft is in one orbit location and switch off this antenna while in another orbit location, would be highly desirable.
In the past, such switches utilized mechanically activated contacts. This type of switch is extensively utilized in present-day satellite applications, but a switch not using contact type switches would be definitely more reliable in a spacecraft environment.
The present invention moves away from the contact switch configuration and utilizes certain characteristics of TEM-Mode, coupled-transmission-line directional couplers in conjunction with a novel switching element introduced into the coupler. A very complete description of this type of directional couplers may be obtained from a reference such as a book entitled MICROWAVE FILTERS, IMPEDANCE-MATCHING NETWORKS, AND COUPLING STRUCTURES, by George L. Matthaei, Leo Young and E. M. T. Jones, McGraw-Hill Book Company, 1964, at Chapter 13.